The problem is reproducible in Chrome v21 also
For example,
1. Open http://docs.sencha.com/ext-js/4-1/#!/example ( memory in TaskManager 110 MB )
2. Open all samples from Chart group ( memory 308 MB )
3. Close All samples tabs
4. Memory is not decreased
5. Open all samples from Grid group ( memory 558 MB )
6. Close all samples Tab
7. Memory is not decreased ( still 558 MB )

is it really ExtJS memory leaking (if extjs in iframe page then brwser doesn't release a memory after iframe destroying)? Or the issue is not related with ExtJS?
Just such issue is not observed with ExtJS 3.x

When I look at the memory consumption, it jumps all over the place, but on my machine (IE9, Win7) it always ends up around 109MB as a settling point. The memory does increase slightly over time, however I see the same kind of behaviour with jquery. Obviously the jumps in memory are less severe because the library is smaller, but it's the same thing on a smaller scale.

The problem is more likely in the application code, since the same thing should be reproducible with just loading the library.

<br>
<br>
When I look at the memory consumption, it jumps all over the place, but on my machine (IE9, Win7) it always ends up around 109MB as a settling point. The memory does increase slightly over time, however I see the same kind of behaviour with jquery. Obviously the jumps in memory are less severe because the library is smaller, but it's the same thing on a smaller scale.<br>
<br>
The problem is more likely in the application code, since the same thing should be reproducible with just loading the library.

<br><br>I've made an example because we are also having problems with memory usage relating to adding and removing Iframes from urls, if you run the example without the ext-js file linked and watch the memory usage while clicking add and remove it'll settle to roughly around what it starts at, maybe 1 or 2k difference which I've always seen drop down to what it starts at after enough time.<br><br>Now if you put the ext-js file reference back and do the same the memory usage goes insane!! i had it up to 200mb+ in a few seconds, this is clearly a leak somewhere in a framework, if Jquery had such a leak the memory usage wouldn't go down but with ext it just keeps going up! is it perhaps because both the child and parent have the ext framework so the child frame interacts with the parent which doesn't get cleaned up on unload of the iframe? If so this is a big problem for us as we use a heavy tab system and once you start using ext controls the memory usage becomes even worse, I had crome at 2gb+ on the sencha examples alone!!<br><br>Are you sure there is nothing that can be done since this is almost a game breaker for us (we are using Ext.Net but the example shows its clearly a JS problem)<br><br>Example:<br>Main page<br>